A position detection system employed on a machine may make use of two inertial measurement units to generate signals indicative of a current position of the machine. In high integrity positioning systems, it may be needed to cross check readings obtained from the two inertial measurement units with each other. This cross checking may be utilized to verify if both or any one of the two inertial measurement units are working satisfactorily. However, in a scenario in which one of the two inertial measurement units has failed, it may be difficult to determine which one of the two inertial measurement units is faulty.
Sometimes, a third inertial measurement unit may be employed to determine the faulty inertial measurement unit. However, by using an additional third inertial measurement unit the overall cost and complexity of the system is increased.
U.S. Pat. No. 8,290,744, hereinafter referred to as the '744 Patent, describes a system for providing fault tolerant inertial measurement data. The system includes a sensor having less accuracy than an inertial measurement unit for measuring an inertial parameter. The system also includes a processor for detecting whether a difference exists between a first data stream received from a first inertial measurement unit and a second data stream received from a second inertial measurement unit. The processor upon detecting the difference determines whether at least one of the first or second inertial measurement units has failed by comparing each of the first and second data streams to the inertial parameter.
However, the '744 Patent includes an additional sensor in addition to the first inertial measurement unit and the second inertial measurement unit. The additional sensor may add to an overall cost and complexity of the system.